Not that you can trust user reviews on iTunes, but one player of Anomaly: Korea recently praised the reverse-tower-defense game as being "one of a kind."
Last year, developer 11 bit studios released a scaled-down version of its reverse tower defense PC game, Anomaly Warzone Earth for the iPad, and it was wonderful. Look how far they've come with the soon-to-be-released sequel, Anomaly Korea.
Last year's Anomaly Warzone Earth flipped the tower defence genre on its head, putting you in the shoes of the guys trying to get past the powers, instead of the guys building them. It was, to keep things brief, brilliant.